预应力桩水平承载性状数值分析

Numerical analysis of lateral response of prestressed piles

预应力桩广泛应用于建筑物桩基础中,单桩水平承载力由于受力条件复杂难以确定。利用大型有限元软件ABAQUS,采用混凝土塑性损伤模型模拟预应力桩水平承载性状,选取上海典型场地软土试桩验证后,进一步分析灌芯以及桩型对水平承载力影响。分析表明:数值计算方法能有效模拟H-y曲线陡降变形,全过程反映预应力桩的水平承载性状;配筋灌芯对单桩承载力影响不大,但能一定程度改善H-y曲线陡降变形;桩型变化对单桩水平承载力影响不大,但能够延缓H-y曲线陡降变形,提高桩身延性。

The pretressed piles are widely used in the construction of structures.Lateral bearing capacity of single pile is difficult to be determined owing to complex stress conditions.A numerical method is proposed based on the plastic damage model for concrete using the software ABAQUS.After validation through the comparison with the in-situ tests,the core grouted condition and variation of pile type are discussed.The analyses show that the numerical method is effective for simulating the lateral response of single pile.The grouted core with reinforcement seldom increases the lateral bearing capacity,but it can improve the steep dipping deflection of H-y curve.The change of pile type can enhance the ductility of pile and reduce the deflection of lateral displacement.